Fall armyworm (Spodoptera frugiperda) migration pathways in the United States

Spodoptera frugiperda (J.E. Smith; Lepidoptera: Noctuidae) or fall armyworm is an important agricultural pest of a number of crops in the western hemisphere. Two morphologically identical host strains of fall armyworm exist, the rice-strain and corn-strain, with the latter inflicting substantial economic losses in corn in both North and South America. Fall armyworm does not survive severe winters so the infestations affecting North America originate from migrants that overwinter in Florida and Texas. A novel haplotype method was developed that could distinguish the corn-strain populations from these two locations and was used to delineate the migratory pathways. The results from three years of surveys will be described. A better understanding of fall armyworm populations and their movement is critical for the development of strategies to predict infestation levels and eventually control this economically important pest in the United States.